Lafayette Reservoir in need of seismic retrofit, could be unstable in earthquake

LAFAYETTE, Calif. (KGO) -- Lafayette Reservoir -- a scenic slice of man-made, idyllic heaven in the hills of Contra Costa County. Aside from nature, the most iconic structure in this earthen dam is a concrete drainage tower.

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"It's been there longer than me!" said one long-time resident.

The dam and tower are ninety years old. But, as earthquake science has evolved, what passed for good enough then is not good enough now, according to the California Division of Safety of Dams, which has downgraded the reservoir's safety rating from satisfactory to fair.

"The dam and tower are the same as when they were built," said The East Bay Municipal Utility District's Chief Engineer, Xavier Arias, who acknowledges that in a strong earthquake along the Hayward Fault, the tower could topple or break, making it impossible to stop water from flowing down a creek to highly populated and prosperous Lafayette.

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"Well I know they were surprised in Oroville when it happened," said John Swerdan who works in a local shopping center. "I would hate to see a mass evacuation from here." His initial reaction is probably much worse than potential realities. East Bay MUD says the creek can contain even the heaviest runoff.

"I would not be concerned," said Arias.

"Would you buy a house down there?" I asked.

"Absolutely," Arias replied.

East Bay MUD notes that its twenty-two other reservoirs passed the state's study with excellent reviews. Only at Lafayette Reservoir did the state find an issue. For now, the utility is looking at ways to stabilize or reinforce the tower.

With the state pressuring them, expect East Bay Mud to spend millions on an expedited fix.

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